Backrest for load handling apparatus



Sept. 10, H. D. OLSON BACKREST FOR LOAD HANDLING APPARATUS 2 Sheets-Sheet 1 Filed May-15, 1967 Ill Harlan D. Olson BY INVENTOR Sept. 10, 1968 H. D. OLSON BACKREST FOR LOAD HANDLING APPARATUS Filed May 15, 1967 2 Sheets-Sheet 2 Ha rlan D. Ulson INVENTOR m v HFIE/XS',

United States Patent r 3,400,965 -BACKREST FOR LOAD HANDLING APPARATUS Harlan D. Olson, Sandy, Oreg., assignor to Cascade Corporation, Portland, 0reg., a corporation of Oregon ,Filed May 15, 1967, Ser. No. 638,421

7 Claims. (Cl. 294-86) ABSTRACT OF THE DISCLOSURE v A backrest for supporting a load held between a pair of opposed relatively movable arms in load-handling apparatus, comprising a frame between the arms formed of multiple guides disposed, one above the other, and elongated fingers telescopically received within the guides. Alternate fingers are pivotally connected at one set of ends to one of the arms and the remaining fingers are pivotally connected at a set of ends to the other arm, and the fingers move in the guides as the arms are moved. The fingers have shoes journaled on other sets of ends which slidewithin the guides to control movement of the fingers.

This invention relates to a backrest for load-handling apparatus, and more specifically to a backrest which has guided telescopic fingers adapted to extendto span the space between a pair of relatively movable, opposed loadgripping arms in such apparatus.

A type of load-handling apparatus presently in use includes a pair of opposed load-gripping arms that are moved toward each other to grip a load and hold it during the transporting of the load. A backrest is often provided intermediate the arms to support the back of the load as it is held by the arms. Various types of backrests have been proposed for performing this support function, including stationary and extensible types, but these have not been entirely satisfactory.

With some backrests, which are mounted independently of the arms with fixed side-to-side dimension, a load is not adequately supported with the arms close together. Other backrests feature a series of fingers extending between and mounted directly on the arms, which move with the arms while providing load support. No gripping arms are entirely rigid and, as a consequence, when the arms are deflected as the result of exerting a large. clamping force, this produces undesirable deflecting of the fingers out of a-common plane. With the fingers deflected outof such acommon plane, damaging ofthe load may result.

A general object of,this invention is to provide a novel backrest for use with load-handling apparatus having opposed clamping arms, which backrest. effectively takes care of the above-outlined diificulties in, a practical and satisfactory manner.

Another object is to provide a novel backrest for such load-handling apparatus, featuring one and preferably multiple elongated fingers extending between opposed clamping arms and mounted on these arms, and a guide frame disposed between the armsoperable to guide the fingers and thus to keep them in place.

A related and more specific object is to provide such a backrest where interspersedfingers mounted at outer sets of ends on the opposed clamping arms have inner ends which are guided for movement in multiple guides disposed ina stationary position between the clamping arms.

It is contemplated that the interspersed fingers indicated abovebe mounted in a position wherein they occupy substantially a common plane. The outer sets of ends of the fingers are pivotally mounted on the opposed clamping arms in such a manner that on the forward ends of the clamping arms deflecting outwardly (as occurs when clamping onto a load) the fingers pivot on 3,400,965 Patented Sept. 10, 1968 their mountings thus to minimize the tendency of the fingers to move out of this common plane. The guides which guide the fingers accommodate longitudinal move ment of the fingers and serve to position the nonpivoted ends of the fingers.

With respect to other specific objects of the invention, the invention contemplates a novel type of guide for each finger which has a compact construction while affording a limited amount of deflection in the fingers (such as occurs when a load is picked up), and a novel construction for guide shoes for the nonpivoted ends of the fingers functioning to guide the fingers on the fingers being moved longitudinally.

These and other objects and advantages are attained by the invention, and the same is described hereinbelow in conjunction with the accompanying drawings, wherein:

FIG. 1 is a top plan view of load-handling apparatus as contemplated, having a pair of elongated, opposed, relatively movable load-gripping arms, a backrest therebetween, part of which is connected to one set of ends of the load-gripping arms, and actuating means for moving the arms;

FIG. 2 is a side elevation view of the load-handling apparatus shown in FIG. 1, with a section broken away better to illustrate the backrest;

FIG. 3 is a view taken along the line 33 in FIG. 2 showing a front elevation view of the opposed loadgripping arms and the backrest;

FIG. 4 is a sectional view taken along the line 4-4 in FIG. 1 (somewhat enlarged), showing a pivotal connection provided between one of the fingers in the backrest and one of the load-gripping arms, and the guided end of a second finger which is connected to the other load gripping arm; and

FIG. 5 is a view taken along the line 55 in FIG. 4 (also somewhat enlarged), showing an end of a guide in the structure, and a finger with shoes journaled thereon disposed in said guide.

i Referring now to the drawings, and first more particularly to FIGS. 1 and 2, at 1 0 is shown generally a load-handling apparatus used for gripping a load While it is being transported.

The apparatus includes a support frame 12 which may be mounted on a transporting vehicle, such as a lift truck (not shown). The support frame includes two pairs of guide bores 14, 1'6 which extend transversely of the frame, and which slidably receive two pairs of guide rods 20, 22. Rods 20 are adapted to extend laterally from one side of the support frame and rods 22 are adapted to extend laterally from the opposite side of said frame.

A pair of relatively movable opposed load-gripping arms, indicated generally at 24, 26, are mounted on the support frame by being secured adjacent their rear ends to guide rods 20, 22, respectively. The two load-gripping arms project forwardly of support frame 12.

The support frame and guide rods are similar to the mechanism disclosed in Farmer et al., 2,844,403. As can be seen with reference to that patent, the structure includes a double-acting hydraulic motor or ram for each load-gripping arm which is utilized in moving the arm to and fro as guided by the rods connected thereto. Conventionally, means may be provided for actuating the rams, whereby both load-gripping arms may be shifted relative to the support frame toward one side or the other of the apparatus to effect side shifting, or the load-gripping arms may be moved toward and away from each other, for the purpose of gripping onto and releasing a load, respectively. Shown at 30 is means connecting the extensible end of a ram to arm 26, and .a similar connection is provided between arm 24 and its associated ram.

Load-gripping arms 24, 26 are similar in construction,

and only one willbe described in detail. Thus, and with reference to arm 26, each may comprise a vertical, elongated, L-shaped member 34, which is secured to guide rods 22. Rigidly secured to the forward lOngitudinal edge of member 34, and projecting forwardly thereof, is an outer member 36. The forward end of member 36 is covered by a deflector cover 38, which is secured in place by fasteners 39.

A somewhat flexible intermediate panel 40 is attached to outer member 36 by suitable means (not shown) with at least its rear end free to be deflected relative to the outer member. A rectangular inner plate 42 is secured to and inwardly of the intermediate panel, with both its rear and forward ends free to be deflected relative to outer member 36. The limited flexibility provided in the various parts of the load-gripping arm allows the arm to give whereby an equally distributed pressure may be applied against a load as is discussed in Farmer et al., 3,145,866, where such an arm is described in detail. As an aid in holding a load gripped between the arms, a friction pad, such as rubber pad 44, is secured to the inner face of inner plate 42.

A limit bar 46 is secured, as by fasteners 48, to plate 42 adjacent its rear edge and above member 36. As is best seen in FIG. 4, in which the limit bar appears in cross section, the upper end of L-shaped member 34 is notched, to provide an upwardly projecting post 34a. When the forward edge of plate 42 is deflected laterally outwardly of the apparatus, its rear edge is deflected laterally inwardly, and limit bar 46, on enough of such deflection, comes into contact with upwardly projecting post 34a.

A backrest constructed in accordance with an embodiment of the invention is indicated generally at 58 in FIGS. 1, 2, and 3. The backrest extends between the loadgripping arms and defines a substantially upright support plane which provides support for the side of a load gripped between the arms.

The backrest includes multiple elongated guides, shown generally at 60, which extend between the load-gripping arms and which are positioned one above the other. As is best seen in FIG. 5, on the second sheet of drawings, each guide includes a pair of opposed parallel bars 62, each of which has flanges along one side. The bars are spaced apart from each other, with the flanges on each bar facing the flanges on the other bar, whereby a guide path or channel is defined therebetween. The spacedapart relationship of the bars results in the presence of an elongated open space which parallels the guide path and faces the forward ends of the arms.

Bars 62, which collectively constitute a guide frame, are mounted in a substantially stationary position on the support frame. More specifically, support columns 68, 70 (see FIGS. 1, 2) project vertically upwardly from the support frame. Affixed to the front edges of columns 68, 70, and extending over the support frame, are mounting plates 72, 74. These plates extend along the back of and have the guides fastened to them. Also providing a mounting for the guides is an intermediate support plate 76 (seen in FIG. 3).

As is best seen in FIGS. 2 and 5, the forward edges of the bars forming the elongated guides lie in a common vertical plane. Between adjacent guides is a flat plate 80 secured along its upper edge to the under side of the upper guide of the adjacent guides, and secured along its lower edge to the upper side of the lower of such guides. Plate 80 is positioned with its front face also lying within the common vertical plane defined by the forward edges of the guides.

The backrest further includes a number of elongated fingers 84, each of which is received Within one of the elongated guides. One end of a finger is pivotally connected to one of the load-gripping arms, and the other end moves within a guide. As seen in FIG. 3, the fingers are interspersed in the backrest, with alternate fingers being pivotally connected-to arm 26 and the remaining fingers pivotally connected to load-gripping arm 24.

Each finger comprises an elongated body of hollow rectangular cross section 86 (see FIG. 5). The connection between a finger and a load-gripping arm is best illustrated in FIG. 4. As is seen in this figure, a connecting lug 88 is secured to and projects from L-shaped member 34 of the arm. The connecting lug has such dimensions that it will fit loosely within an end of the hollow, rectangular body of finger 84. Connecting lug 88 and finger body 86 have accommodating bores receiving a pivot pin 92. Cotter pin 93 holds pin 92 in place. In'the pivot connection described, some play exists between the finger and lug 88, permitting some twisting of the finger about its longitudinal axis. Pin 92 provides a pivot axis accommodating pivoting of the finger relative to the arm to which it is connected about an axis which is normal to the finger and parallels the support plane of the backrest.

With continuing reference to FIG. 4, and considering the upper finger 84 therein illustrated, journaled to each finger adjacent its nonpivoted end is a pair of shoes 94, also referred to as follower means, which act to guide this end of a finger as it is moved by its associated loadgripping arm. As best seen in FIGS. 4 and 5, the shoes are so shaped as to fit snugly between the bars in a guide, with one shoe above and the other shoe below the finger.

Both shoes and the finger have registering holes, which receive a pin 96 journaling the shoes on the finger. As is illustrated in FIG. 5, the mounting for the shoes is such that the nonpivoted end of a finger is carried with its forward side substantially in the plane defined by the forward edges of the guide bars. The guide bars inhibit move-- ment of the shoes or follower means in a direction normal to the support plane of the backrest.

In operation, when the load-gripping arms are moved farther apart from each other, the fingers of the backrest extend from the guides with movement of the arms, to maintain a continuous support spanning the spacebetween the two arms. On the arms being moved together to grip a load, the fingers undergo corresponding movement and telescope within the guides. The shoes journaled on the nonpivoted ends of the fingers keep these nonpivoted ends in essentially a common plane. It will be noted in FIG. 1 that the forward ends of the loadgripping arms toe-in slightly when there is no load being gripped therebetween. However, when the arms are moved together against a load, these forward ends Will be deflected outwardly on hearing against the load. Such deflection causes L-shaped members 34 to twist about upright axes. When such torsional deflection occurs, the pivot connections connecting the fingers to the L-shaped members permit slight relative swinging of the fingers whereby they tend to remain in a common plane. The

open spaces on the forward sides of the guides accommodate displacement of the fingers toward the front edges of the guides.

It should be obvious to those skilled in the art that other embodiments and configurations of the invention are possible without departing from the invention. It is intended to cover all modifications and variations that would he apparent to one skilled in the art, and that come within the scope of the appended claims.

It is claimed and desired to secure by Letters Patentz 1. In load-handling apparatus including a support frame a pair of opposed laterally spaced arms mounted on said support frame for gripping a load, and actuating means connected to at least one of said arms adapted finger to said one arm whereby the finger is movable with said one arm relative to said support frame, said pivot means accommodating pivoting of the finger relative to soid one arm about an axis extending substantially normal to the finger and paralleling the plane defined by said backrest, and an elongated cooperating guide extending between the arms and mounted in a substantially stationary position on said support frame, said guide having means defining a guide path for the finger and the finger including follower means located toward the opposite end of the finger from the fingers said one end which travels along said guide path, said guide having a construction inhibiting movement of said follower means in a direction normal to said plane.

2. The apparatus of claim 1, wherein said finger comprises an elongated body, and said follower means comprises a shoe which is journaled on said body.

3. The apparatus of claim 2, wherein said guide has an elongated opening facing the forward ends of the arms paralelling said guide path and exposing the forward side of the finger, said opening accommodating, on lateral displacement of the finger, movement of the finger therethrough.

4. The apparatus of claim 3, wherein multiple parallel guides disposed one above the other are mounted on said support frame, with front sides substantially in the support plane of said backrest, and multiple fingers are connected to said one arm with follower means traveling in the guide paths of said guides.

5. The apparatus of claim 1, wherein both of said arms are mounted on said support frame for movement relative to the support frame toward and away from each other, the actuating means is connected to both arms and is operable when actuated to move both arms,

multiple elongated guides are mounted on said support frame substantially parallel to each other and disposed one above the other With front sides substantially in the support plane of said backrest, and backrest, and

multiple fingers are provided extending between the arms including one group of fingers movable with one arm pivotally connected at one set of ends to said one arm and another group of fingers pivotally connected at one set of ends to the other arm,

said fingers of the first group being interspersed with the fingers of the second group, there being for each of said fingers an associated guide and each finger having follower means which travels in the guide path define-d in its associated guide.

6. The apparatus of claim 5, wherein said guides have elongated openings facing the forward ends of said arms paralleling the guide paths defined in said guides, said openings exposing forward sides of said fingers and accommodating displacement of the fingers through said openings.

7. The apparatus of claim 6, wherein a guide comprises a pair of parallel spaced-apart bars With an elongated channel defined extending between the bars along their lengths forming a guide path, and the finger associated with the guide is telescopically received within said channel with its follower guided for movement in said channel.

References Cited UNITED STATES PATENTS 2,609,114 9/1952 Backofen et a], 214-653 RICHARD E. AEGERTER, Primary Examiner. R. D. GUIOD, Assistant Examiner. 

